PURPOSE: To make self-running attainable in time of trouble happening, by making the existing analog ignition circuit and monostable circuit so as to be used together with a digital arithmetic unit, while letting a device so as to automatically perform fuel control by output of the monostable circuit in time of trouble happening in the digital arithmetic unit.
CONSTITUTION: An arithmetic unit 10 is constituted so as to output each of pulse signals 16 and 17 based on fuel feed command data and ignition timing command data and a pulse signal based on a command out of a central processing unit 12 from an output circuit 19, respectively. And, a trouble detecting circuit 22, which judges as trouble happens when a period of the pulse signal 19 becomes more then the specified time is installed, while a select circuit 29 being selected by a select signal 23 to be outputted in time of trouble judgment is as well installed. And, in time of being normal, the pulse signal 16 is outputted to an injection valve driving circuit 31 from this select circuit 29 while a pulse signal 27 being outputted from a monostable circuit 26 in synchronous with an ignition signal 25 out of an ignition circuit 24 is also outputted to the injection valve driving circuit 31.
OOBA KATSUHIRO
TSUJII MASAO
OOOKA NAOTO
